#define offset 6    // смещение пина светодиода относительно пина кнопки
#define DELAY_MS 300

#define BUTTON_PIN_2 2
#define BUTTON_PIN_3 3
#define BUTTON_PIN_4 4
#define BUTTON_PIN_5 5
#define BUTTON_PIN_6 6
#define BUTTON_PIN_7 7

#define BEGIN_LED_PIN 8
#define END_LED_PIN 13

bool BUTT = 0;
bool BUTT_FLAG = 0;

void oneClick(short);

void setup() {
  for(size_t i=BUTTON_PIN_2; i<=BUTTON_PIN_7; ++i)
    pinMode(i, INPUT_PULLUP);
  for(size_t i=BEGIN_LED_PIN; i<=END_LED_PIN; ++i)
    pinMode(i, OUTPUT);
}

void loop() {
  oneClick(BUTTON_PIN_2);
  oneClick(BUTTON_PIN_3);
  oneClick(BUTTON_PIN_4);
  oneClick(BUTTON_PIN_5);
  oneClick(BUTTON_PIN_6);
  oneClick(BUTTON_PIN_7);
}

void oneClick(short BUTTON_PIN){
  BUTT = !digitalRead(BUTTON_PIN); 
  if(BUTT_FLAG == false && BUTT == true && digitalRead(BUTTON_PIN+offset) == false){
    BUTT_FLAG = true; 
    digitalWrite(BUTTON_PIN+offset, true);
    delay(DELAY_MS);
  }
  if(BUTT_FLAG == false && BUTT == true && digitalRead(BUTTON_PIN+offset) == true){
    BUTT_FLAG = true;  
    digitalWrite(BUTTON_PIN+offset, false);
    delay(DELAY_MS);
  }
  if(BUTT == false && BUTT_FLAG == true){
    BUTT_FLAG = false;
  }
}